GFR estimation based on standardized creatinine and cystatin C: a European multicenter analysis in older adults.

Abstract

BACKGROUND:

Although recommended by the Kidney Disease Improving Global Outcomes, the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPICR) creatinine equation was not targeted to estimate glomerular filtration rate (eGFR) among older adults. The Berlin Initiative Study (BIS1CR) equation was specifically developed in older adults, and the Lund-Malmö revised (LMRCR) and the Full Age Spectrum (FASCR) equations have shown promising results in older adults. Our aim was to validate these four creatinine equations, including addition of cystatin C in a large multicenter cohort of Europeans ≥70 years.

METHODS:

A total of 3226 individuals (2638 with cystatin C) underwent GFR measurement (mGFR; median, 44 mL/min/1.73 m2) using plasma iohexol clearance. Bias, precision (interquartile range [IQR]), accuracy (percent of estimates ±30% of mGFR, P30), eGFR accuracy diagrams and probability diagrams to classify mGFR<45 mL/min/1.73 m2 were compared.

RESULTS:

The overall results of BIS1CR/CKD-EPICR/FASCR/LMRCR were as follows: median bias, 1.7/3.6/0.6/-0.7 mL/min/1.73 m2; IQR, 11.6/12.3/11.1/10.5 mL/min/1.73 m2; and P30, 77.5%/76.4%/80.9%/83.5% (significantly higher for LMR, p<0.001). Substandard P30 (<75%) was noted for all equations at mGFR<30 mL/min/1.73 m2, and at body mass index values <20 and ≥35 kg/m2. LMRCR had the most stable performance across mGFR subgroups. Only LMRCR and FASCR had a relatively constant small bias across eGFR levels. Probability diagrams exhibited wide eGFR intervals for all equations where mGFR<45 could not be confidently ruled in or out. Adding cystatin C improved P30 accuracy to 85.7/86.8/85.7/88.7 for BIS2CR+CYS/CKD-EPICR+CYS/FASCR+CYS/MEANLMR+CAPA.

CONCLUSIONS:

LMRCR and FASCR seem to be attractive alternatives to CKD-EPICR in estimating GFR by creatinine-based equations in older Europeans. Addition of cystatin C leads to important improvement in estimation performance.

• Authors: Jonas Björk, Sten Erik Bäck, Natalie Ebert, Marie Evans, Anders Grubb, Magnus Hansson, Ian Jones, Edmund J Lamb, Peter Martus, Elke Schaeffner, Per Sjöström, Ulf Nyman
• Journal: Clinical chemistry and laboratory medicine (Clin Chem Lab Med) Vol. 56 Issue 3 Pg. 422-435 (02 23 2018) ISSN: 1437-4331 [Electronic] Germany
• PMID: 28985182 (Publication Type: Journal Article, Multicenter Study)

Chemical References

• Cystatin C
• Creatinine

Topics

• Aged
• Aged, 80 and over
• Cohort Studies
• Creatinine (blood, standards)
• Cross-Sectional Studies
• Cystatin C (blood, standards)
• Europe
• Female
• Glomerular Filtration Rate
• Humans
• Male
• Middle Aged